JPH1097707A - Production of soft magnetic thin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the control of the stresses on the soft magnetic thin films to be applied to the magnetic shielding films and magnetic poles of an MR head or an MR induction type composite head having an MR head part for reproducing and an induction type head part for recording without subjecting these films to a heat treatment at a high temp. at the time of forming the soft magnetic thin films. SOLUTION: The stresses on the thin films described above are controlled by executing the relative movement of a substrate with respect to a target in such a manner that the substrate and the target face periodically each other or applying a negative bias voltage on the substrate or applying the negative bias voltage thereon while executing the relative movement described above in a reactive sputtering stage at the time of forming the thin films composed of metal nitride, such a Fe-Zr-N.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to various magnetic heads such as an induction type magnetic head, a magnetoresistive effect type magnetic head (MR head), and an MR induction type composite head having an induction type head and an MR head. The present invention relates to a method for manufacturing a soft magnetic thin film to be applied.

[0002]

2. Description of the Related Art In recent years, the density of magnetic recording has been increased. Along with this, the development of a thin film magnetic head using a soft magnetic thin film as a magnetic pole and an MR head performing reproduction using a magnetoresistive effect has been actively pursued.

An MR head reads an external magnetic signal by a change in resistance of a read sensor using a magnetic material. The MR head has a feature that a high output can be obtained even in magnetic recording with a high linear recording density because the reproduction output does not depend on the relative speed to the recording medium. M
The R head is usually configured to have a magnetoresistive film (MR film) sandwiched between a pair of magnetic shield films (shield type MR head) in order to increase resolution and obtain good high frequency characteristics.

[0004] Further, since the MR head is a reproducing head, an MR induction type composite head in which an induction type head for recording is integrated with the MR head is usually used.

It is preferable to use a thin film having excellent soft magnetic properties for the magnetic shield film and the magnetic pole of the MR head or the MR induction type composite head. As a thin film with excellent soft magnetic properties,
For example, Japanese Patent Publication No. 7-60767, Japanese Patent Application Laid-Open No. 3-151
There is an Fe-Zr-N-based soft magnetic thin film described in Japanese Patent No.

The MR film generally has low heat resistance. In particular, in a multilayer film (artificial lattice film in which thin films having a thickness of about 5 nm are stacked) exhibiting a giant magnetoresistance (GMR) effect, mutual diffusion occurs between the thin films due to heating. The characteristics are easily deteriorated. Therefore, annealing for improving the soft magnetic properties of the magnetic shield film and the magnetic pole needs to be performed at a temperature lower than 300 ° C.

However, in a metal nitride thin film such as the above-described Fe-Zr-N-based thin film, the compressive stress is large because N, which is a light element, invades between metal lattices.
The stress cannot be released unless heat treatment is performed at a temperature of not less than ° C. Although there is no description about the stress of the film in each of the above publications, practical soft magnetic characteristics are obtained in each of the above publications when the heat treatment temperature is 350 ° C. or higher.
Generally, if the compressive stress is not sufficiently released, for example, when applied to a relatively thick portion such as a magnetic pole of an inductive head portion or a magnetic shield film of an MR head portion, the compressive stress is peeled off from an insulating layer as a base. Even if the soft magnetic thin film itself does not peel, peeling of other thin films may occur. Also,
Problems such as difficulty in obtaining good soft magnetic characteristics due to the influence of magnetostriction also occur.

When a soft magnetic thin film is actually applied to a magnetic pole or a magnetic shield film of a magnetic head, the soft magnetic thin film is strongly affected by the stress of an underlying insulating layer and the like, and an upper layer formed after the soft magnetic thin film is formed. It is also affected by stress. For this reason, even if the stress of the soft magnetic thin film itself is small, it is not always difficult to peel off or the soft magnetic characteristics become good.

Therefore, when forming a soft magnetic thin film applied to a magnetic head having an MR head portion in which the heat treatment temperature must be lower than 300 ° C., no peeling occurs and good soft magnetic characteristics are obtained. In order to achieve this, it is necessary to control the forming conditions so as to have an optimum stress according to the base and the upper layer.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an
When forming a soft magnetic thin film applied to a magnetic shield film or a magnetic pole of a head or an MR induction type composite head having an MR head portion for reproduction and an induction type head portion for recording, a heat treatment at a high temperature is performed. Without controlling the stress of the soft magnetic thin film.

[0011]

This object is achieved by any one of the following constitutions (1) to (5). (1) a step of forming a thin film composed of a metal nitride on a substrate by reactive sputtering, and in the reactive sputtering, the relative position of the substrate to the target is set so that the substrate and the target periodically face each other. A method of manufacturing a soft magnetic thin film, wherein the stress of the thin film is controlled by performing the movement, applying a negative bias voltage to the substrate, or performing the relative movement and applying the negative bias voltage. (2) The substrate is held at a position off the rotation axis of the rotating substrate holder, and the target is periodically opposed to the substrate at a position off the rotation axis of the substrate holder and with the rotation of the substrate holder. The method of manufacturing a soft magnetic thin film according to the above (1), wherein the relative movement of the substrate is performed by fixing the substrate at a position where the soft magnetic film can be moved. (3) Fe, M (M is M
g, Ca, Y, Ti, Zr, Hf, V, Nb, Ta, C
at least one element selected from the group consisting of r, Mo, W, Mn, and B) and N, and in the X-ray diffraction pattern, the intensity I (200) of the diffraction peak on the Fe (200) plane and the intensity of Fe (110) plane diffraction peak intensity I
The ratio I (200) / I (110) to (110) is 0.1
A thin film that is less than 100-
By performing a heat treatment at 280 ° C., the formula (Fe _1-x M _x ) _1-y N _y (x and y represent atomic ratios, 0.01 ≦ x ≦ 0.1, 0.01 ≦ y ≦ 0 .1), and in the X-ray diffraction pattern, I (200) / I (110) is 0.1 or more and less than 1, and the diffraction peak of M nitride is substantially The method for producing a soft magnetic thin film according to the above (1) or (2), wherein an unrecognizable soft magnetic thin film is obtained. (4) A soft magnetic thin film according to any one of the above (1) to (3) for producing a soft magnetic thin film applied to at least a part of at least one magnetic pole of a magnetic head having an induction type head having a pair of magnetic poles. Manufacturing method. (5) Producing a soft magnetic thin film applied to at least a part of at least one magnetic shield film of a magnetic head having a magnetoresistive head having a magnetoresistive film and at least one magnetic shield film. 1)-(4)
The method for producing a soft magnetic thin film according to any one of the above.

[0012]

According to the present invention, when a thin film composed of a metal nitride is formed on a substrate by reactive sputtering, the substrate is moved relative to the target as described above, or a negative Apply a bias voltage or do both.

For example, when the reactive DC sputtering is performed while moving the substrate relatively to the target, the stress of the thin film generally moves in the tensile direction. On the other hand, when the reactive DC sputtering is performed while applying a negative bias voltage to the substrate with high-frequency power, the stress of the thin film generally moves in the compression side. For example, when the substrate is made to revolve as shown in FIG. 5, the stress of the thin film changes as shown in FIG. 6, for example. That is, when the thin film formed on the substrate in the stationary state has a compressive stress (the sign is minus), the stress moves to the pulling side by rotating the substrate, the compressive stress decreases, and the rotational speed increases. Eventually, tensile stress (the sign is plus) is generated. In addition, when a thin film formed without applying a bias voltage to the substrate has a tensile stress, the stress moves to the compression side by applying a negative bias voltage, the tensile stress decreases, and the negative bias voltage increases. Finally, a compressive stress is generated.

In the present invention, when performing the reactive sputtering using nitrogen as a reactive gas, the relative movement is performed on the substrate or a negative bias voltage is applied, so that a maximum of 5 × Width of about 10 ¹⁰ dyn / cm ² (lower limit -4 x 1
The stress of the soft magnetic thin film can be controlled at about 0 ¹⁰ dyn / cm ² , with an upper limit of about 1 × 10 ¹⁰ dyn / cm ² ). Insulating layers formed above and below the magnetic pole and insulating layers formed above and below the magnetic shield film have different thicknesses and shapes, and may be made of different materials.When the thickness of the magnetic pole differs from the thickness of the magnetic shield film There is also. Therefore, although the optimum stress differs between the magnetic pole and the magnetic shield film, according to the present invention, a soft magnetic thin film having the optimum stress can be formed in any case. That is, in the present invention, it is possible to control the stress of the soft magnetic thin film without performing a high-temperature heat treatment, thereby preventing peeling of the soft magnetic thin film and other thin films laminated thereon, Is also improved in soft magnetic properties.

When forming the Fe—Zr—N-based soft magnetic thin film according to the present invention, the composition should be within the above range, and the intensity ratio of the diffraction peak I (2
If the ratio (00) / I (110) falls within the above ranges immediately after the film formation and after the heat treatment, the heat treatment at 350 ° C. or higher is required even when the heat treatment is performed at a low temperature lower than 300 ° C. Soft magnetic characteristics equal to or higher than those of a conventional Fe-Zr-N-based soft magnetic thin film can be obtained.

The metal nitride thin film, particularly the Fe—Zr—N soft magnetic thin film formed according to the present invention is applied to a magnetic pole or a magnetic shield film of an MR head or an MR induction type composite head. The conventional Fe-Zr-N-based soft magnetic thin film requires heat treatment at 350 ° C. or higher as described above in order to obtain good soft magnetic characteristics. Caused deterioration of the MR film. However, the soft magnetic thin film used in the present invention is subjected to a heat treatment at such a low temperature that does not cause deterioration of the characteristics of the MR film, and thus does not cause deterioration of the MR film. For example, as shown in FIG. 1, the trailing side magnetic shield film 6 is formed after the magnetoresistive effect (MR) film 5 in time, so that
When heat treatment is performed on the trailing side magnetic shield film, the MR film is also heated. For this reason, the soft magnetic thin film is particularly suitable for the magnetic shield film on the trailing side of the MR head. Further, for the same reason, it is also suitable for the leading magnetic pole 81 and the trailing magnetic pole 82.

The soft magnetic thin film formed by the present invention, particularly, the Fe-Zr-N-based thin film has low ductility and is hardly stretched. In this regard, it is suitable for the leading side magnetic shield film. When a permalloy film is used for the leading side magnetic shield film, the permalloy film is extended due to contact or collision with a magnetic recording medium such as a hard disk, and a short circuit easily occurs between the permalloy film and the MR film. Thereby, such a short circuit can be prevented, and excellent durability can be obtained. Similarly, a sendust film having low malleability requires a heat treatment at 400 ° C. or more to obtain soft magnetic properties, so that the MR film is damaged. , It has almost no effect on the MR film. In addition, the magnetic shield characteristics when the soft magnetic thin film is used are equal to or higher than those when a permalloy film or a sendust film after high-temperature heat treatment is used.

In a conventional Fe—Zr—N-based soft magnetic thin film, α-Fe precipitates as ZrN precipitates, as described later, so that there is a problem in corrosion resistance. However, since the soft magnetic thin film used in the present invention does not precipitate ZrN, it has good corrosion resistance. For this reason, even when water is used in the magnetic head manufacturing process, it is hardly corroded.

In Japanese Patent Application Laid-Open No. Hei 2-121313, a substrate on which a magnetic thin film is to be formed is disposed outside the rotation axis of a rotary table, and a negative bias is applied to the substrate to apply a negative bias to the rotation axis of the rotary table. A method is described in which a magnetic material is sputtered on the substrate by a sputtering apparatus having a target arranged off-axis. This method
Similar to the present invention in that the substrate is revolved and a negative bias is applied to the substrate. However, the effect of the publication is to impart uniaxial magnetic anisotropy to the magnetic thin film by the inverse magnetostriction effect. Further, the publication only describes an Fe—Ni alloy (permalloy) and does not describe reactive sputtering. In these respects, the invention described in the publication is different from the present invention. This publication discloses, as FIG. 2, a graph showing that the internal stress has changed by changing the bias voltage of the substrate, but the change range of the stress is only about 4 × 10 ⁹ dyn / cm ^2. However, it is significantly smaller than that of the present invention. In a structure in which a number of other layers are stacked above and below a soft magnetic thin film, such as a magnetic head, the soft magnetic thin film needs to cope with a wide range of stresses according to the material and thickness of the other layers. In the described soft magnetic thin film,
Since the change range of the stress is narrow, it is often impossible to cope.
In FIG. 2, the value of the bias voltage is unknown.

Japanese Patent Publication No. 7-60767 does not disclose that the substrate is made to revolve or a negative bias voltage is applied during reactive sputtering. According to the publication, in order to obtain excellent soft magnetic characteristics, the relative intensity ratio of the Fe (200) peak to the Fe (110) peak in X-ray diffraction is 1 or more, that is, (100)
It states that a preferred orientation is essential. FIG. 5 of the publication describes an X-ray diffraction pattern of a soft magnetic thin film that has been subjected to a heat treatment at 600 ° C. In the figure, the relative intensity ratio of the Fe (200) peak to the Fe (110) peak is 3.
It is 1. Also, a broad peak of ZrN is clearly seen in FIG. The mechanism of improving soft magnetic characteristics in the publication is to suppress the growth of crystal grains by depositing ceramic fine particles such as ZrN at the grain boundaries of Fe. In order to precipitate the ceramic microparticles at the Fe crystal grain boundaries, a heat treatment exceeding 300 ° C. is essential. In addition, α-
Since Fe is deposited, there is also a problem that the corrosion resistance is lowered.

The above-mentioned Japanese Patent Application Laid-Open No. Hei 3-1513 does not disclose that the substrate is revolved or a negative bias voltage is applied during reactive sputtering. In the publication, when the heat treatment temperature is 250 ° C., 4
It takes 800 minutes, and the coercive force at that time is as high as 1.4 Oe. FIG. 11 of the publication shows a change in the X-ray diffraction pattern when the heat treatment temperature is changed. According to the figure, when the heat treatment is performed at a high temperature of 450 ° C. or higher, a broad peak of Fe (200) is recognized, but when the heat treatment is performed at a lower temperature region, the Fe (200) peak is reduced. Not substantially recognized, 500 ° C
I (200) as defined in the present invention also after heat treatment at
/ I (110) has not reached 0.1. Also, the publication states that if the heat treatment temperature is 350 ° C. or higher, the coercive force is 1 Oe.
There is a description that a diffraction peak of ZrN is recognized at that time. That is, it is considered that the soft magnetic thin film described in the publication requires the presence of ZrN in order to obtain good soft magnetic characteristics, similarly to the soft magnetic thin film described in Japanese Patent Publication No. 7-60767. 250 ° C in the publication
The fact that the Fe (200) peak does not substantially exist after the heat treatment and the good soft magnetic characteristics as described above are not obtained because the nitrogen content is too high with respect to the composition in the present invention. It is thought that it is.

Japanese Patent Application Laid-Open No. 6-259729 also discloses a soft magnetic thin film having an Fe-Zr-N composition. In this publication, this soft magnetic thin film is applied to a magnetic shield film of an MR head or an MR induction type composite head. The publication does not disclose that the substrate is caused to revolve or to apply a negative bias voltage during reactive sputtering. Further, the publication does not describe that the invention is applied to the magnetic pole of the induction type head. This publication does not describe the stress of the soft magnetic thin film, nor does it describe the X-ray diffraction pattern of the soft magnetic thin film. However, the publication describes that the soft magnetic thin film has a (100) preferential orientation. According to the publication, the soft magnetic thin film is improved in thermal stability because the growth of Fe crystal grains is suppressed by the generation of ZrN. That is, this soft magnetic thin film is one in which ZrN is generated, as in Japanese Patent Publication No. 7-60767 and Japanese Patent Laid-Open Publication No. Hei 3-1513.

However, in the example of the publication, there is no description that the soft magnetic thin film was heat-treated. If heat treatment is unnecessary, it is suitable for an MR head or an MR induction type composite head. However, according to experiments performed by the present inventors, it is extremely difficult to obtain a (100) oriented thin film without performing heat treatment, and film formation conditions such as nitrogen partial pressure during reactive sputtering, input power, Most of the film becomes a (110) orientation film due to minute fluctuations such as the degree of vacuum. Further, since no heat treatment is performed, ZrN cannot be generated stably.
In addition, when heat treatment is not performed and stress control is not performed as in the present invention, film peeling tends to occur, and particularly in the case of a thick film such as a magnetic pole, peeling tends to occur.

[0024]

Embodiments of the present invention will be described below in detail.

The method for producing a soft magnetic thin film of the present invention includes a step of forming a thin film composed of a metal nitride on a substrate by reactive sputtering.

In reactive sputtering, sputtering is performed using an alloy casting target, a multi-target, or the like, and using nitrogen as a reactive gas in an inert gas atmosphere such as Ar. Nitrogen is preferably 0.1 to 1 in the sputtering atmosphere.
The content is 5% by volume, more preferably 2 to 10% by volume.
If the nitrogen content is too low or too high, for example, Fe
In a thin film of a -Zr-N composition, it is difficult to make y in the composition formula described later within the range of the present invention, and it is difficult to obtain good soft magnetic characteristics.

In the reactive sputtering, the substrate is moved relative to the target so that the substrate and the target periodically face each other, a negative bias voltage is applied to the substrate, or the relative movement is performed. Apply a negative bias voltage.

In order to periodically oppose the substrate and the target, a rotating substrate holder is used to hold the substrate at a position off its axis of rotation.
It is preferable that the substrate is fixed at a position off the rotation axis of the substrate holder and at a position where the substrate holder can periodically face the substrate with the rotation of the substrate holder. Specifically, it is preferable to use a substrate holder having a configuration shown in FIG. In the illustrated example, a plurality of substrates 12 are held by a substrate holder 13, and each substrate sequentially faces a target as the substrate holder rotates. This configuration is preferable in that a sputtered film can be simultaneously formed on a plurality of substrates.

The speed of the relative movement of the substrate is not particularly limited. The preferred moving speed is not particularly limited and is not particularly limited, since it depends on various conditions such as the stress of the thin film when the substrate is formed without moving the substrate, the value of the negative bias voltage applied to the substrate, and the material of the substrate. It may be appropriately determined so that a thin film having the stress is formed.For example, when the above-described revolving rotational movement is performed on the substrate, the rotational speed of the substrate holder is generally preferably 20 rpm or less, more preferably 0.5 to 15 rpm. The substrate may be given not only a revolving rotational motion but also a rotational motion.

The same applies to the value of the negative bias voltage applied to the substrate, which depends on various conditions such as the stress of the thin film when the substrate is formed without applying a negative bias voltage, the moving speed of the substrate, and the material of the substrate. It is not particularly limited and may be appropriately determined so as to form a thin film having a desired stress, but is preferably −300 V or more, more preferably −150 to −10 V. In addition,
The power for generating the bias voltage may be DC or high frequency.

There is no particular limitation on the sputtering method.
Although there is no limitation on the sputtering apparatus to be used, magnetron sputtering is preferably used. Sputtering may be performed at a high frequency or at a direct current. However, when the high frequency sputtering is used, the change in stress accompanying the relative movement of the substrate is generally small. Therefore, the direct current sputtering is preferably used. In addition, the operating pressure may be generally about 0.05 to 1.0 Pa. Various conditions such as the sputter input power and the distance between the substrate and the target may be appropriately determined.

The type of the substrate on which the thin film is formed is not particularly limited. The soft magnetic thin film formed according to the present invention is preferably applied to a magnetic pole or a magnetic shield film of a magnetic head described later. In this case, an insulating material made of Al ₂ O ₃ or SiO ₂ , a permalloy, etc. The metal or the like becomes the substrate.

The thin film formed by the reactive sputtering is
It may be crystalline or amorphous.

After the formation of the thin film, a heat treatment is performed if necessary. When the soft magnetic thin film formed according to the present invention is applied to a magnetic head having an MR head, this heat treatment is performed at a temperature lower than 300 ° C. This heat treatment may be for crystallizing the thin film for developing soft magnetic properties, for improving the soft magnetic properties of the crystallized film, or for another purpose. You may.

Although the present invention can be applied to the formation of various metal nitride soft magnetic thin films, it is particularly suitable for forming Fe—N based thin films. It is also preferable that Fe is partially substituted by another metal element such as Ni, Co, and M described later.

Next, an Fe—Zr—N-based soft magnetic thin film, which is a preferred embodiment of the soft magnetic thin film formed according to the present invention, will be described.

This soft magnetic thin film has a composition represented by the following formula.

The formula (Fe _1-x M _x ) _1-y N _y

In the above formula, M is Mg, Ca, Y,
Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W,
It is at least one element selected from the group consisting of Mn and B, preferably at least one element selected from Zr, V, Ta and Ti, and more preferably Zr. Zr preferably accounts for 20 atomic% or more of M. N is nitrogen. x and y each represent an atomic ratio, and satisfies 0.01 ≦ x ≦ 0.1 and 0.01 ≦ y ≦ 0.1, and preferably 0.02 ≦ x ≦ 0.09 and 0.02 ≦ y ≦ 0. .09.

The soft magnetic thin film has a diffraction peak intensity I (200) of the Fe (200) plane in X-ray diffraction.
And the ratio I (200) / I (110) of the diffraction peak intensity I (110) of the Fe (110) plane to 0.1 or more and less than 1;
Preferably it is 0.15-0.8. And, in X-ray diffraction, a diffraction peak of M nitride such as ZrN is not substantially recognized.

When the position of each peak in the case of using CuKα ray in X-ray diffraction is represented by 2θ (θ is the diffraction angle), Fe (200) is about 65 °, Fe (110) is about 44 °, ZrN (200) is about 39 °.

M, especially Zr, is I (200) / I (11
0) is within the scope of the present invention. Also, M
Is effective for miniaturization of the crystal together with N.

In the above formula, if x is too small, the crystal grain size becomes too large, so that good soft magnetic properties cannot be obtained, and the thermal stability also decreases. Also, the corrosion resistance is deteriorated. On the other hand, if x is too large, a high-temperature heat treatment is required for crystallization, and even if it is crystallized, good soft magnetic characteristics cannot be obtained. In addition, the saturation magnetic flux density becomes low.

If y is too small in the above formula, the refinement of the crystal grains by N becomes insufficient, and good soft magnetic characteristics cannot be obtained. If y is too large, when performing a low-temperature heat treatment as described below, a long-time heat treatment that is not practically necessary for crystallization is required, and even if it is crystallized, good soft magnetic characteristics are obtained. I can't.

It should be noted that oxygen is contained in the soft magnetic thin film in a total amount of 5%.
Atomic% or less may be contained.

The composition of the soft magnetic thin film is, for example, Electron P
What is necessary is just to measure by a robe Micro Analysis (EPMA) method.

With the above soft magnetic thin film, excellent soft magnetic characteristics can be obtained. Specifically, the initial permeability at 10 MHz is 100
It can be made 0 or more, and the coercive force can be made 1 Oe or less. Further, the saturation magnetic flux density can be made 14000 G or more.

This soft magnetic thin film is formed by the above-described manufacturing method of the present invention. The thin film formed by the reactive sputtering is usually close to amorphous, and Fe (11
0) There is a broad peak derived from the plane,
A peak derived from the (200) plane is not substantially observed. The peak intensity ratio I (200) / I (11
0) is preferably less than 0.1. Then, by the subsequent heat treatment, the peak intensity ratio is controlled to be within the above range.

After forming the thin film, a heat treatment is performed. This heat treatment is for promoting crystallization of the film and obtaining good soft magnetic characteristics. This heat treatment is preferably 100-280.
C., more preferably at 120 to 260.degree. C., preferably for 0.5 to 20 hours, more preferably for 2 to 8 hours. If the heat treatment temperature is too low, crystallization will be insufficient and good soft magnetic properties cannot be obtained. On the other hand, if the heat treatment temperature is too high, other members of the magnetic head, particularly the MR film, are adversely affected by heat. In particular, an MR film having a multilayer structure in which thin films are stacked
Since each thin film is extremely thin and elements are easily diffused by heating, it is essential to set the heat treatment temperature to the low temperature as described above. By subjecting the film having the above composition to a heat treatment at such a low temperature, an Fe (200) peak appears and I
(200) / I (110) can be set within the range of the present invention, whereby excellent soft magnetic properties can be obtained. If the heat treatment temperature is too high, α-Fe
Precipitates and the corrosion resistance is lowered.

The heat treatment is preferably performed in a vacuum or in an atmosphere of an inert gas such as Ar.

The average crystal grain size of the thin film after the heat treatment is 100
nm or less, and it is easy to set it to 5 to 50 nm. The average crystal grain size may be determined by measuring the half-width W ₅₀ of the Fe (200) peak in X-ray diffraction and using the following Scherrer equation.

Formula D = 0.9λ / W ₅₀ cos θ

In this equation, λ is the wavelength of the X-ray used, and θ is the diffraction angle.

Next, the configuration of a magnetic head to which the soft magnetic thin film formed according to the present invention is applied will be described.

FIG. 1 shows a configuration example of a magnetoresistive head (MR head). FIG. 1 is a plan view as viewed from the magnetic recording medium side, and the relative movement direction of the head with respect to the medium is the lower side in the figure. Therefore, the lower side in the figure is the leading side, and the upper side is the trailing side. 1 includes a leading magnetic shield film 4, an MR film 5 to which a pair of leads 51 are connected, and a trailing magnetic shield film 6 from the substrate 2 in the trailing direction. An insulating material 3 is provided between them.

The above-mentioned soft magnetic thin film may be applied to the leading magnetic shield film or the trailing magnetic shield film, but is preferably applied to both magnetic shield films.

The reproducing head shown in FIG.
Although this is a normal shield type MR head in which the film 5 is exposed on the medium facing surface, the present invention can also be applied to a yoke type MR head having a configuration as shown in FIG. The read head shown in FIG. 2 has a leading magnetic shield film 4, an insulating material 31,
It has a yoke 71, an insulating material 32, an MR film 5, a yoke 72, an insulating material 33, and a trailing side magnetic shield film 6. In this reproducing head, the right side surface in the drawing becomes the medium facing surface, and the magnetic flux passes through the yoke 71, the MR film 5, and the yoke 72.

The above-mentioned soft magnetic thin film is also suitable for an MR induction type composite head having an inductive head for recording and an MR head for reproduction.

The recording / reproducing head shown in FIG. 3 is an example of the configuration of an MR induction type composite head, and has a guiding type head portion on the trailing side of the reproducing head shown in FIG. 1 via an insulating material. This inductive head has the structure of a normal thin-film head having a leading magnetic pole 81 and a trailing magnetic pole 82.

On the other hand, the recording / reproducing head shown in FIG.
The trailing-side magnetic shield film 6 of the reproducing head shown in FIG. 1 is used as a leading magnetic pole of an inductive head, and a trailing magnetic pole 82 of the inductive head is provided on the trailing side. .

When the present invention is applied to these inductive heads, the above soft magnetic thin film is used as a magnetic pole. In this case, the soft magnetic thin film may be applied to the leading magnetic pole or the trailing magnetic pole, but is preferably applied to both magnetic poles. In any of these cases, the soft magnetic thin film does not need to constitute the entire magnetic pole on the leading or trailing side. For example, the magnetic pole may have a laminated structure of the soft magnetic thin film and another soft magnetic thin film such as Permalloy, and the soft magnetic thin film having a higher magnetic flux density may be arranged on the gap side. With such a configuration, a steep magnetic flux change can be realized near the gap.

The configuration of these magnetic heads other than the magnetic shield film and the magnetic pole is not particularly limited, and may be the same as that of a normal MR head or an MR induction type composite head.

For example, the permalloy or the Ni—
In addition to the Co alloy, various materials having a magnetoresistance effect and the like can be used. As described above, since the heat treatment temperature can be reduced in the present invention, it is particularly suitable when the MR film has a multilayer structure. As a multilayered MR film, for example, a spin valve type (NiFe / Cu / NiFe / Fe)
Mn, Co / Cu / Co / FeMn, etc., and an artificial lattice multilayer film (NiFe / Ag, Co / Ag, etc.).

The leads connected to the MR film include Ta and W
For example, it is preferable to use a material that does not diffuse into the MR film.
As the insulating material, ordinary insulating materials such as various ceramics such as Al ₂ O ₃ and SiO ₂ can be used. Also,
The base 2 made of ceramics or the like is usually fixed to the slider of the magnetic head, but the base 2 itself may be used as the slider.

If necessary, a part of the magnetic shield film may be made of various conventional soft magnetic materials such as permalloy.

The dimensions of each part are not particularly limited, and may be determined as appropriate according to the configuration of the magnetic recording medium to be combined. Usually, the magnetic shield film has a thickness of 1 to 5 μm and a width of 30 μm.
２００200 μm, the magnetoresistive film has a thickness of 5-60 nm and a width of 1
10 to 10 μm, the distance between the magnetic shield film and the magnetoresistive film is 0.03 to 1.0 μm, the magnetic pole of the inductive head is 1 to 5 μm, the width is 0.5 to 10 μm, and the trailing magnetic shield film is The distance from the magnetic pole of the induction type head is 0.2 to
5 μm.

In the MR head section, the method of linearizing the MR film is not particularly limited, and can be appropriately selected from various methods such as a current bias method, a hard film bias method, a soft film bias method, and a shape bias method. .

The magnetic head is usually manufactured by forming a thin film and forming a pattern. In forming each film, a vapor deposition method such as a sputtering method or a vacuum evaporation method, a plating method, or the like may be used. Pattern formation can be performed by selective etching, selective deposition, or the like.

The magnetic head is used in combination with a conventionally known assembly such as an arm.

[0070]

EXAMPLES Hereinafter, the present invention will be described in more detail by showing specific examples of the present invention.

A thin film having a stress composition of 88.45Fe-6.70Zr-4.85N (atomic ratio) was formed on a glass substrate by the following procedure.

First, a Fe—Zr—Nr alloy was used as a target, and reactive sputtering was performed while introducing an Ar + N ₂ mixed gas into a vacuum chamber to form a Fe—Zr—N layer having a thickness of 1.0 μm.
A thin film was formed on a glass substrate having a thickness of 300 μm. For the sputtering, an apparatus having a configuration shown in FIG. 5 capable of revolving the substrate in a revolving rotational motion was used. The rotation speed of the substrate and the bias voltage applied to the substrate during the sputtering were as shown in FIG. Note that the bias voltage was applied by applying high-frequency power to the substrate. Flow rate ratio of sputtering _{N 2 / (Ar + N 2} ) is set to 0.1, the gas pressure was 0.20 Pa, the target introduction electric power of 1.4 kW,
The diameter of the substrate is 20 mm and the diameter of the target is 203 mm
The distance between the target and the substrate was 120 mm.

Next, the thin film was subjected to a heat treatment at 250 ° C. for 5 hours.

After the heat treatment, the stress of the thin film was measured. The stress was determined from the amount of warpage of the glass substrate. FIG. 6 shows the results. From the results shown in the figure, it is understood that the stress of the thin film can be largely changed regardless of whether the substrate is rotated or a negative bias voltage is applied to the substrate.

A thin film made of Fe and N was formed in the same manner, and its stress was measured. As a result, the rotation of the substrate and the application of a negative bias voltage resulted in -10 × 10 ⁹ dyn.
/ stress control between the cm ² is up to 5 × 10 ⁹ dyn / cm ^2, was possible.

Magnetic Properties of Thin Film Next, an Al ₂ O ₃ film with a thickness of 10 μm was formed on the surface.
using l ₂ O ₃ -TiC plate as the substrate, to secure the DC bias voltage applied to the substrate to -85 V, a thin film of the composition was formed on the Al ₂ O ₃ film by changing the rotational speed of the substrate was heat-treated The changes in the coercive force Hc and the initial permeability μ at 1 MHz of the thin film were examined. Other conditions and heat treatment conditions during sputtering were the same as described above. FIG. 7 shows the results.
From the figure, it is understood that excellent soft magnetic characteristics can be realized by appropriately setting the rotation speed of the substrate.

X-ray diffraction pattern of the thin film The substrate was rotated at 10 rpm, the bias voltage applied to the substrate was set to -100 V, and a thin film having the above composition was formed.
For 5 hours. The substrate has Al
₂ O ₃ film with Al ₂ O ₃ -TiC plate formed with. FIG. 8 shows X-ray diffraction patterns before and after the heat treatment. In the figure, I (200) /
I (110) was 0.50. For comparison, a thin film was formed in the same manner except that the substrate was not rotated and no bias voltage was applied, and the same heat treatment was performed. Then, the X-ray diffraction pattern was examined. I (2) after heat treatment in this thin film
00) / I (110) was 0.27. These results show that the present invention enhances the Fe (200) peak. No XrN diffraction peak was observed in the X-ray diffraction patterns of either thin film. When the magnetic characteristics of both thin films were measured, the thin film shown in FIG. 8 had a coercive force of 0.2 Oe and an initial permeability at 3 MHz of 3470.
However, in the thin film for comparison, the coercive force was 1.0 O
e, the initial magnetic permeability was 1080.

Comparison by Substrate A substrate having a structure in which an Al ₂ O ₃ film was formed on an Al ₂ O ₃ —TiC plate, a substrate in which a NiFe (permalloy) film was further laminated on this Al ₂ O ₃ film, and a glass substrate were used. After forming a Fe-Zr-N thin film on the surface of each substrate,
For 5 hours. For reactive sputtering,
The number of rotations of the substrate is 10 rpm, and the bias voltage of the substrate is -85.
V. Other conditions were the same as above. For each thin film, the coercive force and the initial permeability at 1 MHz were measured. Table 1 shows the results.

[0079]

[Table 1]

Table 1 shows that the soft magnetic properties of the thin films formed under the same conditions differ greatly depending on the type of the substrate. FIG. 6 plots the number of rotations of the substrate and the value of the negative bias, indicating that the thin film formed under this condition has almost no stress. Nevertheless, when formed on a glass substrate, good soft magnetic properties are not obtained. This indicates that it is necessary to apply an optimum stress to the thin film in consideration of the substrate serving as the base.

When the number of rotations and the value of the negative bias were changed, a thin film exhibiting excellent soft magnetic properties could be formed on the glass substrate, but under the same conditions, the thin film was formed on the Al ₂ O ₃ film. The soft magnetic properties of the formed thin film were not good. Also, by adjusting the rotation speed and the bias voltage,
Even on a permalloy film, it was possible to obtain characteristics superior to those shown in Table 1.

MR-guided Composite Head An MR-guided composite head having the configuration shown in FIG. 4 was manufactured.

First, on a substrate 2 (Al ₂ O ₃ —TiC), an insulating material (Al ₂ O ₃ : thickness 10 μm) and a leading magnetic shield film 4 (Fe—Zr—N thin film of the above composition: thickness) 3 μm), insulating material (Al ₂ O ₃ : thickness 0.1 μm)
m), MR film 5 (15-nm-thick bias film / 7-nm-thick Ta film / 17-nm-thick NiFe film: three-layer structure: total thickness 39 nm, height 2.0 μm), lead 51 (Ta: thickness) 0.2 μm), insulating material (Al ₂ O ₃ : thickness 0.1 μm)
), Trailing side magnetic shield film 6 (F of the above composition)
e-Zr-N thin film: 2.5 μm thick). Both magnetic shield films were formed by reactive sputtering, and heat treatment was performed at 250 ° C. for 5 hours after each film formation. In addition,
In the reactive sputtering for forming the magnetic shield film, the rotation speed of the substrate was set to 10 rpm, and the bias voltage of the substrate was set to -100V. The MR film, insulating material and leads were formed by sputtering. Ion milling was used for pattern formation.

Next, an insulating material (Al ₂ O ₃ : thickness 0.5)
.mu.m) is formed by sputtering to form a gap, and a trailing-side magnetic pole 82 (Fe--Zr--N thin film of the above composition: 3 .mu.m thick) is formed by reactive sputtering.
Heat treatment was performed at 0 ° C. for 5 hours. At the time of reactive sputtering for forming the magnetic pole, the rotational speed of the substrate and the bias voltage of the substrate were as shown in Table 2. Then
An insulating material (Al ₂ O ₃ : thickness 50 μm) was formed by sputtering to form a protective film, and an MR induction type composite head was obtained. Next, the substrate 2 of the MR induction type composite head was fixed to a slider and incorporated in a hard disk drive.

The heat treatment of the magnetic shield film and the magnetic pole was performed in vacuum while applying a magnetic field of 3 kOe parallel to the film surface.

With respect to these magnetic heads, the presence or absence of peeling of the trailing-side magnetic pole from the insulating material was examined. Table 2 shows the results.

[0087]

[Table 2]

From Table 2, it can be seen that the separation of the magnetic pole can be prevented by controlling the number of rotations of the substrate and the bias voltage.

When manufacturing the magnetic head, a step of cutting the substrate while spraying water after the formation of the soft magnetic thin film was provided. No corrosion was observed. In contrast,
When the thin film having the same composition was heat-treated at 350 ° C., rust was observed in the soft magnetic thin film in the magnetic head, which was considered to be due to oxidation of α-Fe.

Incidentally, even when the present invention is applied to the magnetic head having the structure shown in FIGS. 1, 2 and 3, respectively,
The same effect as above was obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a configuration example of an MR head as viewed from a medium side.

FIG. 2 is a sectional view of a configuration example of an MR head.

FIG. 3 is a plan view of a configuration example of an MR induction type composite head as viewed from a medium side.

FIG. 4 is a plan view of a configuration example of the MR induction type composite head as viewed from a medium side.

FIG. 5 is a plan view schematically showing a substrate holder of a sputtering apparatus used in the present invention.

FIG. 6 is a graph showing the relationship between the rotation speed of the substrate, the bias voltage applied to the substrate, and the stress of the formed thin film.

FIG. 7 is a graph showing the relationship between the rotation speed of a substrate and the coercive force and initial magnetic permeability of a formed thin film.

FIG. 8 shows X-ray diffraction patterns before and after heat treatment of a Fe—Zr—N thin film formed by rotating a substrate and applying a negative bias voltage to the substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Substrate 13 Substrate holder 2 Base 3, 31, 32, 33 Insulating material 4 Leading magnetic shield film 5 Magnetoresistive film 51 Lead 6 Trailing magnetic shield film 71, 72 Yoke 81 Leading magnetic pole 82 Trailing magnetic pole

Claims (5)

[Claims] A step of forming a thin film composed of a metal nitride on a substrate by reactive sputtering, wherein the reactive sputtering is performed by using a substrate with respect to the target such that the substrate and the target periodically face each other. A method for producing a soft magnetic thin film, wherein the stress of the thin film is controlled by performing relative movement, applying a negative bias voltage to the substrate, or performing the relative movement and applying the negative bias voltage. 2. A substrate is held at a position off the axis of rotation of a rotating substrate holder, and a target is periodically held at a position off the axis of rotation of the substrate holder and with rotation of the substrate holder. The method for manufacturing a soft magnetic thin film according to claim 1, wherein the relative movement of the substrate is performed by fixing the substrate at a position that can face the soft magnetic thin film. 3. The method according to claim 1, wherein the reactive sputtering is performed to obtain Fe, M
(M is Mg, Ca, Y, Ti, Zr, Hf, V, N
b, Ta, Cr, Mo, W, Mn, and at least one element selected from the group consisting of B) and N, and in the X-ray diffraction pattern, the intensity I of the diffraction peak on the Fe (200) plane I ( 200) and the intensity I (110) of the diffraction peak on the Fe (110) plane, I (200) / I (1).
10) forming a thin film having a value of less than 0.1, and then subjecting the thin film to a heat treatment at 100 to 280 ° C. to obtain the formula (Fe _1-x M _x ) _1-y N _y (x and y And represents a ratio, 0.01 ≦ x ≦ 0.1, and 0.01 ≦ y ≦ 0.1). In the X-ray diffraction pattern, I (200) / I (110) 3. The method for producing a soft magnetic thin film according to claim 1 or 2, wherein a soft magnetic thin film having a ratio of 0.1 to less than 1 and substantially no diffraction peak of M nitride is observed. 4. A soft magnetic thin film according to claim 1, wherein said soft magnetic thin film is applied to at least a part of at least one magnetic pole of a magnetic head having an induction type head having a pair of magnetic poles. Production method. 5. A soft magnetic thin film applied to at least a part of at least one magnetic shield film of a magnetic head having a magnetoresistive head having a magnetoresistive film and at least one magnetic shield film. Claim 1
5. The method for producing a soft magnetic thin film according to any one of the above items 4.